Gayle applauds fans after the game as he carries the match ball after scoring a hat-trick

Birmingham’s best chance actually fell to 18-year-old debutant Corey O’Keeffe just two minutes after he came on.

But the Irish teenager got stage fright when Karl Darlow parried out Che Adams’ long-range strike – the visitors’ first effort on target – and he woefully headed wide with the goal gaping.

So it was left to goal-poacher Gayle to show him how it is done, as Shelvey teed him up after a one-two with Ritchie, and he slotted in first time with his left foot to complete his perfect hat-trick after 77 minutes.

Newcastle’s hero was then immediately taken off by Benitez to a rousing St James’ Park standing ovation.

Blues boss Gary Rowett admitted: “Dwight is a Premier League-class striker, but five years ago when he was playing Bishop’s Stortford he wasn’t.

"We played against him for Burton against Dagenham and Redbridge, and at the time I couldn’t have seen him scoring a hat-trick against a team of mine in the Championship.

“But that’s what desire and drive does for you. He has shown incredible hunger to get better.

“He probably epitomises probably that next level of quality and intelligence that sometimes the top teams have.”

On the drubbing, Rowett added: “It was little bit of a football lesson and a bit of an athletic lesson.

“Make no bones about it, that is a Premier League team we’re playing against.